GOST 23862.12-79
GOST 23862.12−79 Cerium and its dioxide. Chemical-spectral method of determination of iron, cobalt, manganese, copper and Nickel (with Change No. 1)
GOST 23862.12−79
Group B59
INTERSTATE STANDARD
CERIUM AND ITS DIOXIDE
Chemical-spectral method of determination of iron, cobalt, manganese, copper and Nickel
Cerium and its dioxide. Chemical-spectral method of determination of iron, cobalt, manganese, copper and nickel
ISS 77.120.99
AXTU 1709
Date of introduction 1981−01−01
The decision of the State Committee USSR on standards on October 19, 1979 N 3988 date of introduction is established 01.01.81
Limitation of actions taken by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (ICS 11−95)
EDITION with Change No. 1, approved in April 1985 (IUS 7−85).
This standard specifies the chemical-spectral method of determination of iron, cobalt, manganese, copper, and Nickel in the thermodynamic equilibrium and its dioxide.
The method is based on the concentration of impurities by extraction of the macro component — cerium (IV) with tributyl phosphate, treated with bromine, and subsequent spectral analysis of the obtained concentrate.
The interval defined by the mass fraction of impurities:
| iron | from 5·10 |
| cobalt | from 5·10 |
| manganese | from 5·10 |
| copper | from 5·10 |
| Nickel | from 5·10 |
(Changed edition, Rev. N 1).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 23862.0−79.
2. APPARATUS, REAGENTS AND SOLUTIONS
The diffraction spectrograph DFS-13 with a grating 1200 lines/mm operating in the first order reflection, and being a lighting system.
The arc generator DG-2 with optional rheostat or similar, adapted to ignite the DC arc high frequency discharge.
Rectifier AC 250−300, And 30−50, geregistreerde microphotometer MF-2 or similar.
Spectromancer of PS-18 or similar.
Box of organic glass.
Mortar and pestle made of organic glass.
Muffle furnace with thermostat providing temperatures up to 900 °C.
The machine tool for sharpening of electrodes.
Stopwatch mechanical.
Infrared lamp Z-s-1.
Tile electric.
Separating funnel with a capacity of 50, 100, 1000 cm.
Cup platinum with a capacity of 50, 200 cm.
The quartz Cup with a capacity of 30 cmwith lids.
Pipettes with a capacity of 1, 2, 5, 10 cm.
Coals spectral OS-7−3.
Graphite powder of high purity according to GOST 23463−79.
The electrodes are the «glass» turned from coals spectral high purity-7−3 diameter 6 mm: the diameter is 4 mm and crater depth of 5 mm, a height of the outer wall is 6 mm, a wall thickness of 1 mm, a height of the pins is 2 mm, the leg diameter 2 mm electrode 1.
The electrodes are machined from high purity coals spectral-7−3 diameter 6 mm: the diameter is 2 mm and crater depth of 5 mm, a height of the sharpened part is 8 mm, the diameter of the sharpened part 4 mm — electrode 2.
Records of the photographic type II or equivalent, providing normal blackening of analytical lines and the surrounding background in the spectrum.
Rectified ethyl alcohol GOST 18300−87, double-distilled in quartz apparatus.
Nitric acid of high purity according to GOST 11125−84, concentrated, diluted 1:1, 1%, 3 mol/land 1 mol/DM
solutions.
Bromine according to GOST 4109−79, H. h
Nitric acid 3 mol/DMsolution saturated with bromine in separating funnel with a capacity of 1000 cm
800 cm is placed
3 mol/DM
nitric acid, add 30 cm
of bromine and gently stirred for 1 min, then drained (both phases) in a glass jar with a tight-fitting stopper.
Sulfuric acid GOST 4204−77, H. h., diluted 1:1 and 1% solution.
Hydrogen peroxide according to GOST 10929−76, H. h, concentrated and diluted 1:7.
Hydrofluoric acid OS.h. 21−5.
Carbon tetrachloride according to GOST 20288−74.
Tributeby ether phosphoric acid (TBP) technical or h
Ammonia water according to GOST 3760−79, H. h
Sodium carbonate according to GOST 83−79, H. h, solution with a concentration of 100 g/DM.
Deionized water with a specific resistance of 20 to 24 Mω·cm.
Manganese metal according to GOST 6008−90.
Nickel metal stamps PN-1 according to GOST 9722−97.
Cobalt metal brand KP-1 according to GOST 9721−79.
Copper metal brand PMS-GOST 4960−75.
Iron metal according to GOST 9849−86.
Sodium chloride, OS.h. 6−4.
The silver chloride.
Cerium dioxide with a content of the base element not less than 99.99%, a spectral clean-defined impurities.
The cerium nitrate solution with a concentration of 50 g/DM(in terms of oxide): a sample of cerium dioxide with a mass of 10 g is placed in a platinum Cup with a capacity of 200 cm
, moisten with water, add 70 cm
of concentrated nitric acid, 1,5−2 cm
hydrofluoric acid and dissolved in 30 cm
of concentrated nitric acid, dilute with water to volume of 200 cm
and mixed.
The solution of manganese nitrate containing 1 mg/cmmanganese: 0.1 g of manganese metal were dissolved in 10 cm
of nitric acid, diluted 1:1, and the solution transferred to a volumetric flask with a capacity of 100 cm
and the volume was adjusted to the mark with water.
The solution of nitrate of Nickel containing 1 mg/cmNickel: 0.1 g of metallic Nickel dissolved in 10 cm
of nitric acid, diluted 1:1, and the solution transferred to a volumetric flask with a capacity of 100 cm
and the volume was adjusted to the mark with water.
The solution of nitrate of cobalt, containing 1 mg/cmcobalt: 0.1 g of cobalt metal was dissolved in 10 cm
of nitric acid, diluted 1:1, and the solution transferred to a volumetric flask with a capacity of 100 cm
and the volume was adjusted to the mark with water.
A solution of copper nitrate containing 1 mg/cmcopper: 0.1 g of copper metal is dissolved in 10 cm
of nitric acid, diluted 1:1, and the solution transferred to a volumetric flask with a capacity of 100 cm
and the volume was adjusted to the mark with water.
The solution of nitrate of iron, containing 1 mg/cmiron: 0.1 g of metallic iron are dissolved in 10 cm
of nitric acid, diluted 1:1, and the solution transferred to a volumetric flask with a capacity of 100 cm
and the volume was adjusted to the mark with water.
A mixed nitrate solution of 1 containing 0.1 mg/cmmanganese, Nickel, copper and cobalt: in a volumetric flask with a capacity of 100 cm
is administered at 10 cm
nitric acid solutions of manganese, Nickel, cobalt and copper containing 1 mg/cm
manganese, Nickel, cobalt, copper, and the volume was adjusted to the mark with 1%-s ' solution of nitric acid; prepared on the day of use.
A mixed nitrate solution 2 containing 0.01 mg/cmmanganese, Nickel, copper and cobalt: in a volumetric flask with a capacity of 100 cm
is injected to 10 cm
mixed nitrate solution of 1 containing 0.1 mg/cm
of manganese, Nickel, cobalt, copper, and the volume was adjusted to the mark with 1%-s ' solution of nitric acid; prepared on the day of use.
Nitrate solution 3 containing 0.1 mg/cmiron in a volumetric flask with a capacity of 100 cm
are 10 cm in
the nitric acid solution of iron, containing 1 mg/cm
iron, and the volume was adjusted to the mark with 1%-s ' solution of nitric acid; prepared on the day of use.
Spectroscopic buffer: a portion of sodium chloride with a mass of 10 g was mixed with 90 g of powder graphite in a mortar made of organic glass. For homogeneous mixing is conducted in the presence of alcohol.
3. PREPARATION FOR ASSAY
3.1. Purification of tributyl phosphate
In a separating funnel with a capacity of 1000 cmis placed 200 cm
TBP and 600 cm
of sodium carbonate solution, the solutions were stirred for 2 minutes After separation of phases the aqueous layer (bottom) is discarded. The organic phase in the funnel was washed twice with a solution of sodium carbonate in portions of 600 cm
(each time the aqueous phase is discarded). The organic phase is washed four times with 1 mol/DM
nitric acid in portions of 600 cm
, once 400 cm
3 mol/DM
nitric acid saturated with bromine, once 200cm
solution of nitrate of cerium (IV) and then with hydrogen peroxide (diluted 1:7) to the complete removal of cerium. Completeness of removal of cerium control: 200cm
aqueous phase was transferred to a beaker with a capacity of 300 cm
, heated to boiling, and add ammonia solution till the odor. The absence of precipitate indicates the complete removal of cerium.
Next, the organic phase is washed with 400 cm3 mol/DM
nitric acid saturated with bromine, while stirring, for 2 min. the Aqueous phase is discarded. The organic phase (TBP) ready-to-apotre
blenio.
3.2. (Deleted, Rev. N 1).
4. ANALYSIS
4.1. The concentration of impurities
A portion of the sample of cerium dioxide with a mass of 1 g (or the corresponding amount of metal) is placed in a platinum Cup with a capacity of 50 cm, moistened with a few drops of water, add 7 cm
of concentrated nitric acid, 4−5 drops of hydrofluoric acid and dissolved by heating.
To the solution was added 3 cmof concentrated nitric acid, 10 cm
of water and transferred to a separatory funnel with a capacity of 100 cm
, calibrated at 20 cm
. The volume of the solution in the funnel is diluted with water to 20 cm
, adding 25 cm
purified according to claim 3.1 or regenerated (see n.4.3) TBP and vigorously stirred for 1 min. After separation the aqueous phase is transferred into another separatory funnel with a capacity of 50 cm
, and organic collected in a separate utensil for regeneration of the extractant (see p.4.3). To the aqueous phase add 5 cm
of carbon tetrachloride and vigorously stirred for 1 min. After separation the organic phase is discarded and water is poured into a quartz Cup, add 5−8 drops of hydrogen peroxide and evaporated to dryness. To the dry residue in the Cup add 10−15 drops of concentrated nitric acid and 5−6 drops of hydrogen peroxide, and again evaporated to dryness, cover with lids and calcined at 900 °C for 20 min.
In order to avoid pollution of the operation of dissolution and evaporation is carried out in a box with purified air.
Analysis of each sample is carried out in three batches. Simultaneously with each series of tests put two test experience on reagents, guiding them through all stages of the analysis. In this case, the aqueous phase after extraction with carbon tetrachloride is added 50 mg of cerium dioxide and act as above.
After calcination, the residue in the Cup was cooled to room temperature and then subjected to spectral analysis.
(Changed edition, Rev. N
1).
4.2. Spectral analysis of concentrates
On the bottom of the crater of the graphite electrode is placed successively 2 mg of silver chloride, and then without stirring injected every concentrate impurities or 50 mg of the sample comparisons. The electrode with the sample or the reference sample serves as the anode, it is installed in the lower holder tripod spectrograph. The top electrode is the electrode of the N 2-filled buffer mixture. Between the electrodes ignite the arc DC 20−21 A. the Distance between the electrodes is 3 mm. the Spectra are photographed on a spectrograph DFS-13 using photographic plates of type II. The width of the spectrograph slit is 23 microns, exposure time 30 s. an Intermediate diaphragm in the condenser being selected so that blackening of the background near analytical lines were in normal pochernenija.
In the same conditions photographed three times the spectra of concentrates of samples analysed, three times the spectra of each reference sample and of cerium dioxide, twice the spectra of the concentrates obtained from control experiments.
Exposed photographic plates show washed with water, fixed, washed in running water (15 min) and dried.
4.3. Regeneration of used extractant
In a separating funnel with a capacity of 1000 cmadds 200 cm
used TBF, 600 cm
of hydrogen peroxide diluted 1:7, and gently stirred for 2 minutes After separation of phases the aqueous phase is discarded. TBF treatment with hydrogen peroxide diluted 1:7, is repeated until the complete removal of cerium (see p.3.1).
After complete removal of the cerium to the organic phase are added 400 cm3 mol/DM
nitric acid saturated with bromine, and vigorously stirred for 2 min. After separation of the phases, the aqueous phase is discarded and TBF is ready to use.
5. PROCESSING OF THE RESULTS
5.1. In each spectrogram photometric blackening of analytical lines of the designated element (see table.2) and the surrounding background
and calculate the difference of pochernenija
;
;
for samples comparison, find the arithmetic mean value
and build a calibration curve in the coordinates (
,
).
Table 2
| The designated element |
Wavelength of analytical lines, nm |
| Manganese |
279,487 |
| Nickel |
305,062 |
| Cobalt |
345,35 |
| Copper |
327,396 |
| Iron |
302,064 275,014 |
For the calibration graph and the values for the concentrates of the sample and concentrates control experiments find the average values of the mass fractions determined by impurities
and
in percent.
5.2. Mass fraction of the element () in percent is calculated by the formula
where — mass of the concentrate of the impurities, mg;
— the weight of the portion of the sample, mg;
the average value of the mass fraction of the element in the concentrates of the sample, %;
the average value of the mass fraction of the element in concentrates in the reference experiment, %.
5.3. Discrepancies in the results of three parallel measurements (the ratio of largest to smallest), and the discrepancy between the results of the two analyses (the ratio of largest to smallest) should not exceed values of allowable differences specified in table.3.
Table 3
| Determined by the impurity |
Mass fraction, % |
The permissible divergence |
| Iron |
5·10 |
3,0 |
1·10 |
2,8 | |
3·10 |
2,8 | |
| Cobalt |
5·10 |
3,0 |
1·10 |
2,5 | |
5·10 |
2,4 | |
| Manganese |
5·10 |
3,5 |
1·10 |
3,0 | |
| Manganese |
5·10 |
2,4 |
| Copper |
5·10 |
3,2 |
1·10 |
3,0 | |
5·10 |
2,5 | |
| Nickel |
5·10 |
2,7 |
1·10 |
2,6 | |
5·10 |
2,5 |
(Changed edition, Rev. N 1).
